FIG. 1 shows an example of a schematic configuration of a radio base station apparatus 1 for use in a mobile communication system A.
As shown in FIG. 1, the radio base station apparatus 1 includes a modulation/demodulation function section MDE-A for the mobile communication system A, an optical feeder transmission/reception apparatus OF-TRX and an antenna ANT.
Note that, the modulation/demodulation function section MDE-A for the mobile communication system A is located indoors in a station building; the antenna ANT is located outdoors in a high place; and the optical feeder transmission/reception apparatus OF-TRX is located in the vicinity immediately below the outdoor antenna ANT.
In addition, in order to reduce signal transmission loss, optical fiber is used to connect the modulation/demodulation function section MDE-A for the mobile communication system A to the optical feeder transmission/reception apparatus OF-TRX.
In recent years, it has been demanded that a single radio base station apparatus as shown in FIG. 1 should provide services not only in the mobile communication system A, but also in a mobile communication system B having a frequency band close to that of the mobile communication system A.
In order for the radio base station apparatus 1 shown in FIG. 1 to provide services in both the mobile communication system B and in the mobile communication system A as described above, it is conceived, as shown in FIG. 2, that a modulation/demodulation function section MDE-B for the mobile communication system B is added to the configuration of the radio base station apparatus 1 shown in FIG. 1, and that a shared optical feeder transmission/reception apparatus (hereinafter, shared OF-TRX) shared by the mobile communication systems A and B is also added thereto instead of the optical feeder transmission/reception apparatus OF-TRX shown in FIG. 1.
Note that, the modulation/demodulation function section MDE-B for the mobile communication system B is located indoors in the station building, while the shared OF-TRX is located in the vicinity immediately below the outdoor antenna ANT in the same manner as the optical feeder transmission/reception apparatus OF-TRX shown in FIG. 1.
In addition, in order to reduce signal transmission loss, optical fiber is used to connect the shared OF-TRX to the modulation/demodulation function section MDE-A for the mobile communication system A to the modulation/demodulation function section MDE-B for the mobile communication system B.
Patent Document 1: JP-A-2003-115793